battle alert

例句：

1. 1. The military has issued a battle alert for the area.
   军方已经对该区域发布了战斗警报。
2. 2. The war is still ongoing, so we should be on alert for any sudden changes in the situation.
   战争仍在进行中，我们应该随时准备应对任何突然的变化。
3. 3. The soldiers were all on battle alert, ready to defend their country at a moment's notice.
   士兵们都处于战斗状态，随时准备保卫国家。